Nanomicelle-generating Microneedles Loaded With Tranilast for Treatment of Hypertrophic Scars in a Rabbit Model.

Abstract

Hypertrophic scars (HS) are the result of pathological wound healing characterized by a red, raised scar formation. The goal of this research was development of a new method for treatment of HS formation. A tranilast-loaded microneedle (TMN) was developed and applied in a rabbit ear model to treat an induced HS. Scar elevation index, the thickness of dorsal skin by hematoxylin and eosin staining, collagen deposition by Masson trichrome staining and expression of myofibroblast biomarker proteins were evaluated. The 12×12 array of the TMN containing 2.9 μg tranilast per needle released more than 80% of the drug within 30 min. During the procedure, control, non-loaded MN and TMN loaded with three different doses of tranilast (low: 2.5-3, medium: 25-30, and high: 100-150 μg) were applied to the HS in rabbit ears. High-level TMN led to a clear and natural appearance of skin, a decrease in scar elevation index by 47% and decline in the thickness of the epidermis from 69.27 to 15.92 μm when compared to the control group. Moreover, the collagen density also decreased in groups treated with medium- or high-level TMNs, by 10.2% and 9.06%, respectively. Furthermore, the expression of transforming growth factor-β, collagen-1, and α-smooth muscle actin proteins was reduced in TMN-treated HSs compared to the control. The findings show the overall efficacy of TMNs in inhibiting HS. Thus, use of TMN is a simple and cosmetic remedy for HS, with good protection and reliability.